Julia wrote 20 letters each month for y months in a row. write an expression to show how many total letters julia wrote.

Rational numbers are the numbers which can be written as fraction of a/b ,where a,b be any integer and b≠0. They are finite and recurring decimals.

For example:- 0.2 is a rational number and can be written as 2/10 or 1/5.

Irrational numbers are the numbers which can not written as fraction and they are non-terminating .

For example: The √2 [square root of 2] is also an irrational number. After simplifying,it would be written as 1.41421356237…so on ,but the numbers go on into infinity and do not ever repeat, and they do not ever terminate.